WO2013120648A1

WO2013120648A1 - Method for the temporary connection of a product substrate to a carrier substrate

Info

Publication number: WO2013120648A1
Application number: PCT/EP2013/050849
Authority: WO
Inventors: Jürgen Burggraf; Gerald MITTENDORFER
Original assignee: Ev Group E. Thallner Gmbh
Priority date: 2012-02-16
Filing date: 2013-01-17
Publication date: 2013-08-22
Also published as: CN104115267A; DE112013000980B4; AT517748A5; CN104115267B; SG11201404960TA; US20140374144A1; DE102012101237A1; JP2015507373A; KR20140128976A; US9390956B2; JP6140194B2; KR102061369B1; DE112013000980A5; AT517748B1

Abstract

The invention relates to a method for the temporary connection of a product substrate (2) to a carrier substrate (6), comprising the following method steps: - application of a connecting layer (5) onto a product substrate-accepting side (60) of the carrier substrate (6) in a connecting surface section (13) of the product substrate-accepting side (60), - application of an anti-adhesion layer (4) having a low adhesive force onto a connecting side (2u) of the product substrate (2) in an anti-adhesion surface section (15) of the connecting side (2u), the area of which at least partially, in particular predominantly, preferably substantially entirely corresponds to the area of the connecting surface section (13), wherein an accepting space (14) delimited by the connecting layer (5) and the carrier substrate (6) as well as the product substrate (2) and the anti-adhesive layer (4) is formed for receiving structures (3) that protrude from the connecting side (2u) and that are provided on the connecting side (2u) of the product substrate (2), - alignment of the product substrate (2) relative to the carrier substrate (6) and connection of the connecting layer (5) to the anti-adhesive layer (4) on a contact surface (16).

Description

Method for temporarily connecting a product substrate to a

carrier substrate

Description

The invention relates to a method according to claim 1 for temporarily connecting a product substrate to a carrier substrate.

Working with structures such as chips stocked

Product substrates are often required in the semiconductor industry and may include mechanical and / or chemical or other processing steps (lithography, lacquering, coating, etc.) as well as transports of the product substrates from A to B.

In addition, there is an enormous miniaturization pressure with ever larger radii of the product substrates (200mm, 300mm, yes up to 450mm) in order to further increase the component density. It is easy to imagine that Handling this extremely thin product substrates causes considerable technical problems.

Depending on the carrier materials used and the

used connecting layer between the carrier and the product substrate are various methods for dissolution or destruction of the

Bonding known, such as the use of UV light, laser beams, temperature or solvent.

The detachment is increasingly becoming one of the most critical

Process steps, since the thin substrates with substrate thicknesses of a few μιη easily break during peeling / peeling or suffer from the forces necessary for the process of detachment.

In addition, the thin substrates have little to no dimensional stability and typically curl without support material. While handling the mostly on back-thinned wafers based

Product substrates is therefore virtually a fixation and support of the wafer practically inevitable.

Known methods for temporary bonding of a product substrate to a carrier substrate for easy detachment of the wafer, for example, on double-sided adhesive films, liquids, wax or similar substances, so that the product substrate can be separated as easily and low energy from the carrier substrate after processing. Such methods are disclosed in US Pat. No. 5,725,923

US2007 / 01 84630, EP1286385A2 and US5,863,375.

The following technical problems exist when temporarily connecting: 1. High material consumption partly expensive materials.

2. High temperatures for temporary bonding and therefore high energy requirements.

3. Time-consuming removal processes, especially in chemical

Separation / dissolution of the bonding layer, especially in wet-chemical processes, which are usually expensive, environmentally harmful and therefore inefficient. The chemical dissolution also happens that not completely dissolving the

Bonding layer before detachment of the product substrate, some places continue to be adhesive and then lead to the destruction of the product wafer when peeling at these locations.

4. Cleaning of the product substrate after peeling necessary.

It is therefore an object of the present invention to provide a method for bonding a product substrate as non-destructively as possible and with the least possible energy expenditure on a carrier substrate, and with which the product substrate can also be easily detached again from the carrier substrate.

This object is achieved with the features of claim 1.

Advantageous developments of the invention are specified in the subclaims. The scope of the invention also includes all

Combinations of at least two of in the description, the

Claims and / or the figures given characteristics. For given value ranges, values lying within the stated limits should also be disclosed as limit values and be claimable in any combination. The invention is based on the idea to apply an anti-adhesion layer instead of the carrier substrate on the product substrate, in particular in areas which are not covered with chips, preferably on

Peripheral edge of the product substrate, more preferably in a region on the opposite side of the carrier substrate

Connection layer is provided.

In this way it is possible according to the invention, on the carrier substrate by the connecting layer and the carrier substrate a

To form receiving space for provided on the product substrate structures, in particular chips.

According to the invention, the non-stick layer is dimensioned and designed so that when contacting with the bonding layer on the

Carrier substrate acts a sufficient for processing and transport of the product substrate adhesive force.

With product substrate is a product substrate, for example a

Semiconductor wafer, which is usually thinned to a thickness between 0.5 .mu.m and 250 .mu.m, is tended to become increasingly thinner product substrates.

The carrier used is, for example, a carrier substrate having a thickness of between 50 μm and 5,000 μm, in particular between 500 μm and 1000 μm.

According to a preferred embodiment of the invention it is provided that the connection surface portion on the side of the circumference

Carrier substrate, in particular in one, preferably for Product substrate receiving side concentric, ring portion, is arranged. By homogeneous or evenly distributed over the respective surfaces application of the bonding layer and / or the release layer on the side of the product substrate and / or

Carrier substrate, in particular in a, preferably concentric, ring section, the product substrate is attached to the carrier substrate with the least possible effort and is just as easily detachable from this, without damaging the structures present on the product substrate.

Advantageously, the structures are at least partially, preferably completely, surrounded by the non-stick layer. In this way, the structures are at the same time protected from the outside by the non-stick layer

Protected influences.

According to a further advantageous embodiment of the invention it is provided that a detachment of the product substrate from the carrier substrate by applying at least one of the carrier substrate

predominantly centric or at least predominantly laterally on a side of the product substrate receiving side facing away from the release side of the

Carrier substrate acting tensile force takes place.

It is particularly advantageous if the tensile force is applied by means of a release side, in particular the entire surface, sucking, preferably flexible carrier holder. As a carrier holder is particularly suitable a chuck, in particular a spinner chuck for receiving the carrier substrate, in particular by means of negative pressure, for example

Suction pads, holes or suction cups. Alternatively, a mechanical recording, for example by lateral brackets, conceivable. In a further, alternative embodiment, the recording takes place

electrostatically. Particularly in the case of temporary detachment, a flexible carrier holder is advantageous, so that the detachment of the product substrate can take place in a particularly gentle manner, while a rigid carrier holder is conceivable in the event of lateral detachment.

A product substrate holder is, in particular similar, preferably identical in construction, as the carrier holder designed and brings a the

Carrier holder opposite force on the product substrate,

especially full surface, on.

As far as the detachment concentric from one to the receiving space

facing inside of the contact surface, this relates to the variant of the centric loading of the carrier substrate during detachment, in particular in conjunction with the flexible carrier holder. This is a particularly gentle, piece by piece evenly from

Center to the circumference peeling achieved.

By contrast, it is conceivable with advantage in the variant of the predominantly lateral detachment of the product substrate from the carrier substrate or vice versa of the carrier substrate from the product substrate to provide a release by mechanical release means, whereby the beginning of the detachment is less jerky and thus gentler for the product substrate.

According to the invention, it is advantageously provided that the adhesion force acting between the connecting layer and the non-stick layer lies between 0.1 mJ / m ² and 10 J / m ² , in particular between 1 mJ / m ² and 1 J / m ² , wherein the adjustment is made by the choice of material and the size of the contact surface.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings; these show in:

Fig. 1: a schematic representation of an inventive

Process flow

2 shows a schematic side view of a product substrate connected to a carrier substrate according to the invention,

Fig. 3: a schematic representation of the invention

Detaching the product substrate from the carrier substrate in a first embodiment,

Fig. 4 is a schematic representation of the invention

Detaching the product substrate from the carrier substrate in a second embodiment.

In the figures, the same components and components with the same

Function marked with the same reference numerals.

FIG. 1 describes a method sequence according to the invention for temporarily connecting one with structures 3, in particular one

Topography, preferably at least partially consisting of chip-stocked product substrate 2, with a substrate substrate 6. The process is in the plane of the drawing from left to right up to a finished product substrate-carrier substrate composite. 7 In the supporting substrate 6, in a connecting surface portion 13 of a product substrate receiving side 6o of the supporting substrate 6, a ring-shaped concentric to the product substrate receiving side 6o is formed

Connecting layer 5 is applied, which extends from the side periphery 6s of the support substrate 6 inwardly. The bonding layer 5 protrudes from the product substrate receiving side 6o.

In particular, parallel to this, preferably simultaneously, is applied to a connection side 2u of the product substrate 2 in a

Non-stick surface portion 15 applied an anti-adhesive layer 4. The non-stick layer 4 extends from a side circumference 2s of the

Product substrate 2 inside, forming a concentric

Ring section. The ring width 4b of the non-stick layer 4 approximately corresponds to the ring width 5b of the connecting layer 5. The non-stick layer 4 also protrudes from the connecting side 2u. The non-stick layer 4 surrounds, in particular encloses, at the same time the structures 3 applied on the connection side 2u.

The ring width 4b and / or ring width 5b is advantageously between 1 mm and 25 mm, in particular between 5 mm and 15 mm.

Subsequently, the product substrate 2 is rotated by 180 degrees, so to speak upside down, in order to mechanically and / or optically align the product substrate 2 with the non-stick layer 4 in a further step with respect to the carrier substrate 6 with its bonding layer 5. Subsequently, in a further process step, the

Non-stick layer 4 is temporarily connected to the connection layer 5 at a contact surface 16.

According to Figure 2, the inventive solution is the,

Non-stick layer 4 only on the edge, so peripherally and not over the entire surface of the product substrate 2 and / or the carrier substrate 6 to apply. The structures 3, in particular dices of the product substrate 2, in particular a product wafer, are located within the annular non-stick layer 4. The connecting layer 5 with

correspondingly strong adhesive action is also applied to the carrier substrate 6 peripherally and corresponding to the non-stick layer 4. After contacting, a receiving space 14 for receiving the structures 3, in particular a sealing layer, is formed by the product substrate 2 and the respective annular bonding layer 5 and adhesive layer 4 applied to the respective side perimeter 2s and 6s and the carrier substrate 6, the thickness 4d of the non-stick layer 4 and the thickness 5d of the connecting layer 5 together form the height H of the receiving space 14, which is higher according to the invention than that

Structures 3 on the product wafer 2, so that the structures 3 the

Do not touch carrier wafer 6. The thickness 4d is advantageously greater than the thickness of a monolayer and less than 5 .mu.m, in particular less than 2 microns. The thickness 5d is in an advantageous embodiment between 1 .mu.m and 1000 .mu.m, in particular between 5 .mu.m and 500 .mu.m, preferably between 10 .mu.m and 200 .mu.m. By adjusting the thickness 5d, the height H of the receiving space 14 can be adapted to the height of the structures 3.

The contact surface 16, which forms the temporary connection between the carrier substrate 6 and the product substrate 2, has a lot smaller area than in the previously known methods and peeling only those between the non-stick layer 4 and the

Bonding layer 5 acting adhesive forces are overcome, which are large enough, the product substrate 2 and the carrier substrate 6 during processing and during transport

hold together, but with relatively little effort again are separable, especially since the contact surface 16 occupies only a small part of the total area of the product substrate receiving side 6o and / or the connection side 2u.

For detachment of the product substrate 2 from the carrier substrate 6 after carrying out corresponding processing steps or transport, two preferred embodiments according to the invention are shown in FIG. 3 and FIG. 4, which differ in particular in the position of introduction of the tensile force to overcome the adhesive force on the carrier substrate 6.

In the embodiment shown in FIG. 3, the detachment of the product substrate 2 from the carrier substrate 6 takes place at least predominantly on a peripheral portion of the side circumference 6s with a tensile force that faces away from the product substrate receiving side 6o by a rigid carrier holder 12

Ablöseseite 6u is transferred to the carrier substrate 6. As a result, the support substrate 6 is released from the product substrate 2 fixed to a peripheral side portion of the product substrate 2 by a product substrate holder 9 on a holding side 2o facing away from the connection side 2u, by overcoming the adhesion force acting between the connection layer 5 and the release layer 4

Contact surface 16 in this peripheral portion. Would the traction at Using a rigid support holder 12 not laterally, but rather be applied centrally, the adhesion to the entire contact surface 16 would have to be overcome substantially simultaneously, which would lead to a greater stress on the product substrate 2 by a higher tensile force. The tensile force to be applied, in particular at the beginning, can be assisted by releasing the connection between the connecting layer 5 and the non-adhesive layer 4 in the region of application of the tensile force, ie from the side, in particular by mechanical separating means, for example a blade or a wedge, so that the traction can be further reduced.

Both the carrier holder 12 and the product substrate holder 9 preferably work via suction paths 8, which form the product substrate 2

or the carrier substrate 6 as homogeneously as possible, in particular over the whole area, on the detachment side 6u of the carrier substrate 6 or the holding side 2o of the product substrate 2.

4, a flexible, in particular elastic, carrier holder 12 'is used for detaching the carrier substrate 6 from the product substrate 2, wherein the tensile force on detachment of the carrier substrate 6 on the carrier substrate 6 is applied predominantly centrally, so that the In contrast to the detachment according to FIG. 3, detachment does not start from the outside but from an inside 16i of the contact surface 16.

The detachment is thus carried out concentrically from the inside, ie from the center, to the outside, wherein the bending of the carrier substrate 6 along the product substrate receiving side 6o by the elasticity and thickness of the carrier holder 12 'is adjustable. In the embodiment shown in FIG. 4, it is particularly important that the suction webs 8 on the release side 6u of the carrier substrate 6 act as close as possible to the side circumference 6s of the carrier substrate 6, in particular on the rear side to the connecting surface section 13, around the

Carrier substrate 6 during the detachment securely on the flexible carrier holder 12 'to fix.

The detachment is carried out by a detachment device 1, which consists of a fixed to supports 1 1 receptacle 10 for receiving the

Product substrate holder 9 and the product substrate holder 9 and a vacuum device, not shown, for connecting the suction paths 8 is formed. Furthermore, the detachment device 1 has a

Carrier holder 12, 12 'with the described tensile force acting on robotics, in particular in the form of a robot arm, on, which is not shown.

As a main component of the carrier substrate is advantageous

selected according to the invention one or more of the following materials: Si, glass, ceramic. As the main constituent of the non-stick layer / compound layer S, one or more of the following materials are selected according to the invention: polymers, metals, low-viscosity materials, films.

License plate

1 detachment device

2 product substrate

2o holding side

2s page size

2u connection side

3 structures

4 non-stick coating

4b ring width

4d thickness

5 bonding layer

5b ring width

5d thickness

6 carrier substrate

6o product substrate receiving side

6s page size

6u transfer page

7 Product substrate-carrier substrate composite 8 Suction structure

9 product substrate holder

10 recording

11 columns

12, 12 'carrier holder

13 connecting surface section

14 recording room

15 non-stick surface section

16 contact area

16i inside

H height

Claims

Patent claims

1. A method for temporarily connecting a product substrate (2) to a carrier substrate (6) with the following method steps:

- Applying a compound layer (5) on a

Product substrate receiving side (6o) of the supporting substrate (6) in a joining surface portion (13) of the product substrate receiving side (6o),

- Applying a non-adhesive layer (4) with low adhesion force on a connection side (2u) of the product substrate (2) in one with the connection surface portion (13) at least partially, in particular at least predominantly, preferably in

Substantially completely, surfaceally corresponding non-adhesive surface portion (15) of the connection side (2u), wherein a of the connection layer (5) and the carrier substrate (6) and the product substrate (2) and the non-stick layer (4) limited receiving space (14) for receiving at the connection side (2u) of the product substrate (2) provided by the

Connecting side (2u) protruding structures (3) is formed,

- Aligning the product substrate (2) relative to the carrier substrate (6) and connecting the connecting layer (5) with the

Non-stick layer (4) on a contact surface (16).

2. The method of claim 1, wherein a connecting surface portion (13) on the side circumference (6s) of the carrier substrate (6), in particular in a, preferably to the product substrate receiving (6o) concentric, ring portion is arranged.

3. The method according to any one of the preceding claims, wherein the non-stick surface portion (15) on the side circumference (2s) of the

Product substrate (2), in particular in a, preferably to the non-adhesive surface portion (15) concentric ring portion, is arranged.

4. The method according to any one of the preceding claims, wherein the structures (3) at least partially, preferably completely, are surrounded by the non-stick layer (4).

5. The method according to any one of the preceding claims, wherein a detachment of the product substrate (2) from the carrier substrate (6) by acting on the carrier substrate (6) with an at least predominantly centric or at least predominantly laterally on one of the product substrate receiving side (6o) facing away from the release side ( 6u) of the carrier substrate (6) acting tensile force takes place.

6. The method according to claim 5, wherein the tensile force by means of the release side (6u), in particular full-surface, sucking, preferably flexible support holder (12, 12 ') is applied.

7. The method according to any one of claims 5 or 6, wherein the detachment concentrically facing from one to the receiving space (14)

Inside (16i) of the contact surface (16) takes place.

8. The method according to claim 5, wherein at the beginning of the at least predominantly lateral detachment takes place by mechanical release agent.

9. product substrate-carrier substrate composite (7), consisting of

a supporting substrate (6) having a connecting layer (5) applied to a product substrate receiving side (6o) of the supporting substrate (6) in a connecting surface portion (13) of the product substrate receiving side (6o);

one with the carrier substrate (6) along a contact surface (16) between the connecting layer (5) and one on a

Connecting side (2u) of the product substrate (2) in one with the connection surface portion (13) at least partially

areal corresponding anti-adhesive surface portion (15) of the connecting side (2u) applied anti-adhesive layer (4)

connected product substrate (2), wherein in one of the

Connection layer (5) and the carrier substrate (6) and the product substrate (2) and the non-stick layer (4) limited

Receiving space (14) on the connecting side (2u) of

Product substrate (2) provided, from the connection side (2u) protruding structures are accommodated.